Dear Freesurfer Community,

I have a question regarding the formatting of the FSGD file while doing an analysis with Xhemi.

First the --y file was created as previously explained in another discussion (https://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg63965.html). That is, mris_preproc with --xhemi and no --fsgd flag.

If I understood correctly, that would create a mgh file with the following order: sub01lh, sub01rh, sub02lh, sub02rh...

Then the FSGD file while running mri_glmfit would be:

GroupDescriptorFile 1

Title xxx

Class sub

Variables   var1

Input   sub01lh   sub   var1_lh_sub01

Input   sub01rh   sub   var1_rh_sub01

Input   sub02lh   sub   var1_lh_sub02

Input   sub02rh   sub   var1_rh_sub02

Would this be correct? If so, what would be the best case for specifying a variable like age? Just repeating the value 2 times?

As always, thanks in advance

Kind Regards

José